Familial lipoprotein disorders and premature coronary artery disease.

Although there is consensus that lipid variables, especially lipoprotein(a), are heritable and that elevated LDL cholesterol levels should be treated, there are no clear definitions of the common familial lipid disorders associated with premature CHD (lipoprotein(a) excess, FCH, familial dyslipidemia, familial hypoalphalipoproteinemia, familial hypercholesterolemia), nor do we have clear guidelines for the treatment of most of these disorders. Implementation of therapy for elevated LDL cholesterol in familial lipid disorders often has not occurred even in the United States. Before recommendations can be made for subjects with lipoprotein(a) excess and HDL deficiency (who often have combined hyperlipidemia or hypertriglyceridemia), prospective studies documenting benefit of CHD risk reduction must be carried out in subjects with lipoprotein(a) excess and HDL deficiency. One such study is being carried out with gemfibrozil in CHD patients with HDL deficiency. Current data do justify treatment of CHD patients with lipoprotein(a) excess with niacin because niacin has been shown to lower lipoprotein(a) levels as well as lower CHD risk mortality in random CHD patients. With regard to CHD patients with or without HDL cholesterol levels less than 35 mg/dL (0.9 mmol/L), efforts should be made to optimize their lipid profile and reduce their LDL cholesterol levels to less than 100 mg/dL (2.6 mmol/L).